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CEPD discusses design for beach renourishment

By TIFFANY REPECKI / trepecki@breezenewspapers.com - | Feb 16, 2021

The Captiva Erosion Prevention District’s commission learned about the design matrix recommended by its engineering firm for the upcoming beach nourishment project at its meeting, as well as heard from the Sanibel-Captiva Conservation Foundation on its potential role and a possible research project.

On Feb. 8, the commissioners heard from Tom Pierro with Coastal Planning & Engineering, a subcontractor for APTIM Engineering. He gave an update on the design and preparation for the 2021-22 project, including a suggested design pick, as well as the bid volume and bidding approach.

Pierro started off by reviewing the firm’s engineering and design report for the project produced in 2018, which outlined factors like renourishment interval, erosion rate, sand fill volume and a discount for flexible construction. The total project cost ranged from about $26.81 million to $28.31 million.

The CEPD had been considering an option that included traditional construction, 900,000 cubic yards of fill plus 16,100 cubic yards for dunes and a 10-year interval, at the cost of about $28.31 million.

Pierro continued that the firm has since created five matrix models, with their associated costs, by incorporating a beach condition survey from October. It then adjusted the various factors, such as using an eight-year versus 10-year renourishment interval, no dune fill or a reduced 10,000 cubic yards, and applying the discount. It also calculated in an annual erosion rate of 57,300 or 73,700 cubic yards.

He explained that based on the matrixes, the firm came up with its design recommendation for the CEPD. It also offered two more options, which incorporated 25 percent more and 25 percent less fill.

The suggested design consists of a 10-year interval, an erosion rate of 73,700 cubic yards and the placement of 600,000 cubic yards of fill, with dune fill to be determined, at a cost ranging from about $20.47 million to $21.97 million. The lower end includes that flexibility for “time of completion.”

Pierro noted that it provides a 12-month window to start, with the project done in six months.

“This is the one that’s going to drive that mobilization price down,” Pierro said, referring to offering flexibility as a way of reducing the high cost associated with assembling the required equipment.

He added that the recommended design will offer the biggest bang for the buck.

Chairman Rene Miville questioned the drop from 900,000 cubic yards to 600,000 cubic yards.

Pierro explained that the 2018 report was based on the 2017 beach conditions and depended on what the projected erosion would be like in 2020. However, three years later, the firm has new surveys.

“The beach performed better than what was expected,” he said.

Secretary Harry Kaiser voiced support for proceeding with the recommended 600,000-cubic-yard design, while Commissioner Mike Mullins thought it may be beneficial to put more sand down.

Treasurer Dick Pyle asked when the project would go out to bid.

Pierro explained that if the commission concurred with proceeding on the suggested design, the firm would send out a pre-solicitation letter in the coming week to alert potential bidders of the project.

“So companies are on notice,” he said.

Pierro added that there was still some additional work to do on the contract.

“We’ll probably go out to bid in a month or so,” he said.

The commission informally gave the firm the green light to proceed. A special meeting has been scheduled for Feb. 19 at 1 p.m. at the SCCF to hold a formal vote, plus discuss other items.

SEA TURTLE NEST MONITORING, RELOCATION

On a related note, SCCF Chief Executive Officer Ryan Orgera provided the commissioners with an overview of what it would charge the CEPD for its staff to monitor and relocate sea turtle nests in the project area if the beach renourishment occurred during the island’s upcoming turtle nesting season.

“A lot will depend on the bids you get back and timing,” he said.

Orgera reported that the maximum cost to the CEPD for the work will be $176,700, which covers $2,000 for technician training, $56,700 for 18 weeks of daily monitoring, $114,00 for up to 190 “peak” nest relocations (April 15 to July 31), and $4,000 for up to 10 “off-peak” ones (Aug. 1 to Oct. 31).

He continued that should the project occupy at least 45 days of peak sea turtle nesting season, the minimum pricing in order to carry out the state and federal requirements would be $120,000.

Orgera explained that the work will require a minimum of three biologists, as its volunteers cannot be used per the state’s guidelines. He added that SCCF will adjust the pricing based on the final plan.

The commission is expected to vote on the proposal on Feb. 19.

After Orgera’s presentation, Coastal Wildlife Director Kelly Sloan spoke about proposed sea turtle research that the SCCF would like to conduct in conjunction with the CEPD’s renourishment project.

She explained that the hatch success documented on Captiva has averaged 53 percent — a range of 40.2 percent to 73.5 percent — over the last 10 years, after nests subjected to predation and other losses are removed. Sea turtle nests laid on non-nourished stretches of Sanibel had an average hatch success of 69 percent using the same criteria, suggesting that Captiva provides less suitable nesting habitat.

“We’re proposing a project to evaluate the low sea turtle nesting,” Sloan said.

The four specific objectives would be:

– Characterize the physical properties of sand — color, size, bulk density and compaction — on renourished and natural stretches of beach on Sanibel and Captiva.

– Evaluate how these variables influence groundwater flow, temperature and moisture inside the nest cavity.

– Characterize the effects of elevation, beach slope and width on nesting success on Sanibel and Captiva.

– Evaluate how these covariates impact embryonic development, nest fate and hatching/emergence success.

The SCCF has estimated that the equipment and laboratory analysis services will cost about $65,000 for the project. It is seeking $45,000 from the CEPD, with SCCF covering the remaining $20,000.

The commission is expected take up the matter on Feb. 19.

IN OTHER NEWS

– Executive Director Jennifer Nelson reported that the CEPD has sold the LuxuryLav Trailer to Prestigious Restrooms for $33,000. Staff estimated that the project cost about $54,675 total to date, including $42,376 for the trailer, $10,110 for engineering, and $2,189 for 15 months of storage.

“We sold the trailer,” she said. “We did take a loss.”

Nelson noted that she plans to meet with the county to talk about a permanent structure.

Mullins questioned if the associated Lee County TDC funds would need to be returned.

“I do not have an answer on that,” she said, adding that she will find out.

– The commission voted 4-0 to accept the CEPD’s annual audit for fiscal year 2019-20.

– During January, a total of 1,851 tickets were sold, with $54,325 collected in parking meter revenue. During the same month last year, a total of 3,263 tickets were sold, with about $36,181 collected.